It just depends on how organized people get. Take for example an attack on a bio lab the other day. The NC had about the same numbers as the TR, but were just spawning and rushing a point that the TR had dug into heavily. Me and a squad of around 5 or 6 others set up another sunderer right beside one of the teleporters on one of the outer bases and were able to keep grouping up and getting in and kept getting behind their lines taking out a bunch of em and almost took down their spawn gen before we got rushed by ~20 TR, but the majority of the NC were spawning at the "closer" sunderer that was right under the bio lab, and it took them several minutes to run down and then up the lift pads and then in through the air vehicle pad, which had a few dozen TR set up with engineer guns and maxs mowing everyone down as they trickled in two or three at a time.
Even after we kept saying over the region chat nobody would spawn at the farther away sunderer and come with us. After a bit the other sunderer got destroyed and suddenly everyone began spawning at our sunderer. About half of them apparently had no idea that the teleporter was right there beside the sunderer and ran in on foot (despite us yelling "Take the teleporter, it's right here!"), but the other half rushed in with us at the teleporter. During that few minutes that people were going in that way we managed to get in and take all three points and were about to get the spawn control down with steady reinforcements teleporting in constantly, when suddenly we started getting pushed back and I stopped getting spawn bonuses for my sunderer and it seemed like the NC presence up top just dried up almost instantly. When I finally died I found out what happened: someone deployed another sunderer "closer" under the dome again and everyone began spawning there instead, making us lose our foothold inside. They quickly pushed us back out and capped the three points back and the assault on the landing pad from the other route began again, with the TR quickly entrenching with engineer guns and mowing people down in 2s and 3s as they trickled in.
If we had been a bit more organized (there were a bunch of squads around, but ours seemed to be the only one even remotely organized, all the rest were just bum rushing in 2s and 3s and half of the squads in the area were split between that continent and Esamir with no organization at all) we could have easily taken that base.